Definition of rudiment in English:

noun

It neglects the fact that although the rudiments of a task can be picked up quite soon, skills take time to develop, and the process is inhibited by too many job changes, compulsory task rotations, or rapid staff turnover.

Teaching pupils the rudiments of double-blind tests, clinical trial methods and general principles of factoring studies for other influences would clear these scientific confusions.

They might just about have grasped the rudiments of e-mail, but they haven't a clue about the new media.